1. Field of the Invention
The present invention is directed in general to communications systems and methods for operating same. In one aspect, the present invention relates to the devices and methods for reducing power consumption of a client node when performing channel monitoring operations within a heterogeneous wireless-enabled communications environment.
2. Description of the Related Art
Today's next generation cellular networks, such as those based on Third Generation Partnership Program (3GPP) Long Term Evolution (LTE)-Advanced (LTE-A), generally involve implementation of heterogeneous communication technologies. In these implementations, low power network nodes are typically placed to overlay traditional high-power Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (eNB) nodes to expand network coverage and to increase system capacity. Currently, two types of implementations have been discussed. The first is macro-pico, where a low-power picocell is accessible to all client nodes. The second is macro-femto, where a low power femtocell is only accessible by a predetermined group of client nodes having a closed subscription.
In these implementations, if a different carrier frequency is used for the pico/femtocell than that which is used for the macrocell, then it is referred to as a carrier aggregation (CA)-based heterogeneous implementation. Since a different frequency band is used for the pico/femtocell transmission and reception, client nodes using the pico/femtocell experience minimum interference from the macro eNB. Likewise, client nodes using the macro eNB experience minimum interference from the picofemto eNB. However, CA-based heterogeneous implementations require the acquisition of two separate radio frequency bands, which could prove to be inconvenient and costly. Accordingly, use of the same carrier transmission frequency for both macro and pico/femtocells, referred to as a non-CA-based heterogeneous implementation, is desirable for efficient use of radio resources.
For a non-CA-based heterogeneous implementation, the picocell, femtocell and macrocell share the same radio frequency spectrum to provide services to the client node. Full frequency reuse is possible in such implementations, which could maximize the system spectral efficiency. However, frequency reuse among picocells, femtocells and macrocells could cause strong inter-cell interference and degrade system performance. As a result, enhanced inter-cell interference coordination (eICIC) for non-CA-based implementations have been proposed as a work item in 3GPP to improve the interference condition of a heterogeneous network. Yet current implementations of eICIC incur additional processing operations that result in higher power consumption, which in turn reduces a client node's battery reserves. In view of the foregoing, it would be advantageous to conserve client node battery reserves when eICIC techniques are implemented in a non-CA-based implementation.